Method of dial-sinking.



No.y 762,082.

N0 MODEL.

C, B. NICHOLS.y

PATENTED JUNE 7, 1904.

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@aMSN/Z371' yf/ARLES ,BN @Hors `UNITED STATES Patented June 7, 1904.

`PATENT OFFICE.

METHOD OF DIAL-SINKING.

SPECIFICATION forming part of Letters Patent No. 762,082, dated June '7, 1904. Application filed February 2, 1903. Serial No. 141,530. (No model.)

To all whom t may concern:

Beit known that I, CHARLES B. NICHOLS, a citizen of the United States,residing at Springfield, in the county of Sangamon and State of Illinois, have invented a certain new and useful Method of Dial-Sinking, of which the following is such afull, clear, and exact description as will enable persons skilled in the art to which it appertains to understand and practice my said method.

My invention relates to the art of dial-sinkform a complete dial, as hereinafter fully explained. y K

In order that the nature and scope of my invention may be clearly understood, it is necessary to briciy describe the art as commonly known and practiced prior to my invention.

Theprocedure heretofore commonly practiced in making a double-sunk dial is substantially as follows: Two copper disks of the full size of the dial and one smaller copper disk somewhat larger than the finished size of the second bit are providedand are coated on both sides with suitable enamel, and the enamel is baked thereon in amanner which is well known in the art. The central part of one of the largerenameled disks is then cut away to form the opening for the center piece and the opening for the second bit. The procedure in` cutting out these partsr is as follows: The outline of the opening is {irst cut through the enamel on both sides of the disk down to the copper by means of a copper lap and flour of emery. After cutting through the enamel as described a glass tube or a wall of wax is placed around the opening, forming a cup, into which nitric acid is poured, and the acid burns away the copper so as to detach the parts of the disk which are to be removed. These detached parts being smaller than the opening in the plates from which they were taken cannot be used in the construction of the dial. Hence the material of these parts and the labor of coating' with enamel and burning same goes to waste. A second enam eled disk is then taken, and the outline of the center piece, somewhat larger than the opening in the lirst disk, is cut through the enamel, and the copper is burned away with acid cxactly the same as was done with the first disk.v In cutting out the center piece from the second disk the outer rim of the enameled disk goes to waste. The second bit is then cut and burned out of a third disk in exactly the same manner. Under this procedure two enameled disks, the full size of the dial, are

Aused to make the rim-piece and the center piece of a single dial, and a considerable part of the enameled disk from which the second bit is made goes to waste. When the several parts of the dial are formed as described, they are soldered together in a well-known manner.

A prime purpose of my invention is to avoid the waste of material and labor incident to the method which I have j ust described.

To make my invention effective, I employ structural elements of a dial substantally as shown Yin the annexed drawings, to which refence is hereby made and in which similar reference-letters designate like parts in the several views. p

Referring tothe drawings, Figure l is a top plan of a complete dial embodying my invention. Fig. 2 is an Venlarged vertical section on the line 2 2 of Fig. 1. Figs. 3, 4, and

5 are respectively a top plan of the center piece, a top plan of the second bit, and a top plan of the rim-piece, of a double-sunk dial.

Fig. 6 is a vertical transverse section on the line 6 6 of Fig. 3. Fig. 7 is a vertical transverse section on the line 7 7 of Fig. 4. Fig. 8 is avertical transverse section on the line 8 8 of Fig. 5. Figs. 9 and 1() are top plans of modified .forms of the-rim-piece and center piece, respectively. Fig. 1l is a vertical section on the line 1l ll of Fig. 3.

A double-sunk dial embodying my invention consists of three partsviz., a rim-piece A, a center piece B, and a second bit l). The foundation of the piece A is an annular sheet lOO . are covered with enamel c.

-of the plate being coated with enamel. y The part D consists of a copper disk (Z, having an upturned circumferential wall al and coated on both sides with enamel (Z2. The copper plate is somewhat larger than the central opening in the plate A, and the copper plate plates.

d is somewhat larger than the second-bit opening formed by the conjunction of the parts A and B. rIhe part B is made larger than the opening in order that when the wall a, of the plate A. is removed and the internal edge of the plate is iinished as hereinafter described the perimeter of the wall 7/ of the copper plate will contact with the inner edge of the copper platel a. so that the plates may be conveniently soldered together as hereinafter described. For the same purpose the plate Z also is somewhat larger than the opening to which it is to be fitted. 4In practice I have found that copper plates are most suitable for the purpose; but plates of other suitable material may be used without departing from my invention.

The procedure in the practice of my method is as follows: Suitable plates a, L, and d, having upturned walls, as described, are first provided. The upturned walls a and ai of the plate e, the upturned walls L and b2 of the plate I), and theupturned wall d of the plate al are preferably formed by. pressing the parts out of sheet copper by means of suitable dies in a manner well known in the art and which need not be described here. The means for producing the upturned edges is immaterial. It is essential only that the edges of the enamel on the upper face of all of the parts shall be completely surrounded by an upturned wall, preferably of the material of the plate, as described. 'Ihe plates are then coated on both sides with enamel, the surface of the enamel on the upper or face sides of the plates being flush withthe upturned walls of the The under side of the rim-plate A is not entirely covered with enamel; but a space around the inner edge of the plate, as indicated by the dotted line in Fig. 5, is

left bare to form an opening large enough to receive the center piece B and the second bit D without the necessity for removing the enamel from the underside of the plate. The enamel on the under side of the center piece B does not extend fully up to the concave perimeter of the center piece; but a part of the plate is left bare, as indicated by the dotted line in Fig. 3, to form a recess in which the second bit D lits without the necessity for removing the enamel. The enamel veaose is then baked on the plates, and the dials are painted in the usual manner. A glass tube or a wall of wax of such size and shape that the part B will fit loosely therein is placed on the back of the part A, surrounding the upturned edge (o2. Nitric acid is then poured in the glass tube or the cup formed by the wall of wax, and the acid burns away the copper, so as to leave a ledge of enamel projecting inwardly beyond the copper and leave an opening in the copper, in which the part B will tit without any treatment of or work on the part B. The inner edge ofthe enamel of the part A is then beveled and polished by grinding with flour of emery in the usual manner. The copper wall b' of the part B is then soldered to the copper a. of the part A. I preferably solder the parts together; but they may be united by any suitable means without departing from my invention.

In making' a single-sunk dialthat is, a dial having a rim-piece A, as shown in Fig. 9, and a second bit, as shown in Fig. 4, but not having a center piece-the steps above described will complete the construction of the dial. In making a single-sunk dial without a second bit the center-piece shown in Fig. l0 may be used. The procedure in making the doublesunk dial is exactly the same, except that previous to soldering the center part B tothe partA a suitable glass tube or wall of wax is placed on the back of the part B around the segmental upturned wall Z22, and the copper is burned away with nitric acid to form an opening in the copper in which the part D will lit. 'Ihe part D is then soldered to the parts B and A.

In practice it is 'necessary to surround the enamel with an inclosing rim or wall of copper to prevent cracking and scaling of the enamel during the operation of burning, and this fact has caused the resort to the expedient, universally practiced before my invention, of cutting the rim-piece out of one enameled dial, then cutting the center piece out of another enameled dial, then cutting the second bit out of a third enameled disk, and then securing all o f the parts together.

My method entirely dispenses with th'e cutting through the enamel on both sides of the dial to make the openings for the center piece and the second bit and also materially reduces the use of acid in burning away` the copper and results in great saving of time, labor, and material.

Having fully described my invention, what IOO I claim as new, and desire to secure by Letters the dial, and securing the center plate in the opening in the rim-plate, as set forth. n

2. The herein-described method for dialsinking, consisting in forming on a copper rim-plate for dials upturned Walls extending around the external and internal edges of said plate, forming on a copper center plate for dials upturned walls extending around the external and internal edges of said center plate, coating said plates with enamel, baking the enamel on said plates, burning away with nitric acid the inner upturned wall of the rimplate and soldering the center plate in position in the opening in the rim-plate, as set forth.

3. The herein-described method for dialsinking, consisting in forming on a rim-platey for dials upturned walls extending around the v external and internal edges of said plate, forming on a center plate for dials upturned walls extending around the external and the internal edges of said center plate, forming 0n the second bit of a dial an upturned wall extending around said second bit, coating said rimplate, center piece and second bit with enamel, baking the enamel on said rim-plate, center piece and second bit, removing the internal wall from said rim-plate, removing the segmental part of the external Wall of the center piece, and securing together said rim-plate, center piece and second bit, as set forth.

4. The herein described method for dialsinking, consisting in forming .on a copper rim-plate for dials upturned walls extending around the external and internal edges of said rim-plate, forming on a copper center plate for dials upturned walls extending around the external and the internal edges of said center plate, forming on a second bit for dials an upturned wall extending around the outer edge of said second bit, coating said rim-plate, center plate and second bit with enamel, baking the enamel on said rim-plate, center plate and second bit, cutting away with nitric acid the upturned inner wall of the rim-plate, cutting away with nitric acid the segmental part of the external upturned Wall of said center plate and soldering together said rim-plate, center plate and second bit, as set forth.

In witness whereoil I have hereunto signed my name, at Springlield, Illinois, this 23d day of January, 1903.

CHARLES B. NICHOLS.

Witnesses: a

` MAUDE CRAIG, N. DU Bols. 

